Draft-regulator



H. V. STEVENS.

DRAFT REGULATOR.

APPLICATION FILED IuNEI. 1920.

1,391,348. l Patenasept. 20,1921.

2 SHEETS-SHEET l.

Cl ttozmug H. V. STEVENS.

DRAFT REGULATOR.

APPLICATION FILED IuNE, 1920.

1,391,348. I Pantedsepr. 20,1921.

2 SHEETS-SHEET 2.

II. I

UNITED STATES P.frialar OFFICE.

HENEYv. STEVENS, or EMroRIA, KANSAS.

nnAr'rREGuLA'roR.

Specification of Letters Patent.

PatentedlS'e'pt. '20, :1921.

cntixiaiin of appicatinsrial110,284,756, md Marci; 24,1919. Tins pbiieatin inea june 7,ir92to.

' seran Noyesegssa.

To @ZZ whom'z't 'may concern Be it'kn'own" that I, HENRY V. S'rEvENs, afc'itizenV of the United States, residing at Emporia, inthe' county of Lyon and State of Kansas, have invented certain new Vand useful 'Improvements in Draft-Regulators and I' do declareV the following to be afull, clear,"and exact description of the invention, such vas will enable others skilled in the art to which it app'ertains tomake land use the same, reference being hadA to the accompanying drawings, and 'to the letters and figures of reference markedthereon, which form a part of this specication.

This application is a continuation of application Serial No. 284,756,'filedby me on or about March 24, 1919 for draftregulator The inventionfrelates to ydraft control for steam boiler furnaces and the invention primarily vcontemplates the provision" of mentof air through the lfire-'box and while means for automatically controlling the velocity'of the air passingthrough' the firebox of a furance in proportion'td the pressure maintained in the boiler or steam' space. For example, in locomotive practice, the combustion of vthe fuel is usually augmented by a forced draftV consisting of a nozzle adjacent to the smoke lstack operating as an injector to cause 'a rapid displacesucha forced draft promotes'rapid combus tion of the fuel andconsequently effects a relatively quick risein steam generation, it is also a wasteful means of maintaining the 'steam at a desired pressure.

. I have provided meanswhereby the'draft generated in the f firebox and consequently, the velocity of the -moving air, maybe varied by variations in the steam pressure in the boiler; consequently, whenthe steam pressurein the boiler is high or' has reached Substantially its maximum, the velocity of the moving air will be relatively lowv and 4 5.

f the ai-r velocity will increase to accelerate inversely, (when the' steam 'pressure fis'l low,

the lcombustion ofthe fuel a'fd'thereby bring the steam 'up to the desired pressure. By using Va v"device embodying the principles here involved, therate of combustion maybe proportioned in inverse 'ratio to the steain pressure in the boiler.

Inthe drawings,

Figure 'I -isfaA sidev elevational view of a locomotive'boiler and 'furnace to which ymy invention is applied.

Fig. II is a transverse' sectional EView through laj smoke box.

' Fig. iii is a A@fue envenena View f a lubricating cup and part of "a `lubrficating pipe leading fromfithe"fountainfo thereon# ri lviii is a` Semoun' View' en the uney VII -VIIIof Fig'. V. n

'Referring now to the drawings :by "nu-V merals of reference:

v1 designates a steam boiler as, for example,

such as isi'a'pplicableto locomotives, 2 being: the fire-box and l3 theV cab. Adjacent to the forward end ofthe' smoke box-is smoke stack 4, beneath which isa draft krcontroller surrounding the ejectornoZZle 31,"cmmon to this type offurnace, foreffecting a "forced draftto the' 'fire boX 2. Leading from the dome 5 above ythe steam space'ofthe boiler is a discharge pipef which communicates with a cylinder7 having a constant pressure valve "ChamberSnnd a. pistn'chai'nber` 9,

'the two being divided Avby the partition 10 intermediate the ends' of the cylinder. The springf'chainber 8 maybe by'pas'sed bya passage 11, best seen' in Fig. IV, and in said chamber 8 is a lspringy 12, one end o fiwhich isadapted'toabut against thepartition 10 'andthe other end of whichis "adapte'd'to bear against the Ypiston valve 13 having slidinginovement to close off or'permit com- Inunicationbetweenfthe pipe 6 and 'the bypass 11.y Within the chamber 9fis 'a piston 14 having a pi'stn'stem,` or `rrod 15 V,terminating in a vrack 116, guided in a guide bracket 17, the rack havingteeth `1'8'meshing with a gear '19`o`nja shaft 20 carried bythe bracket17, and theig'e'r 19 meshing with a smaller gear '21 on a shaft 22,Afa'ls`o carried by the wing 23 of thebracket 17.V

The bracket 17 ispreferably bolted'to the upperend'l of the y cylinder 7, 'as shown, 4the bolts 24'serving both as securing means for the bracket and 'for fastening the 'cylinder head 25 to the lcylinder 7; therefore, when it isdesired to take the' controllerv actuator apart for inspection or 'rep'airs, it will be I only necessary to remove the bolts and head 25.

vSecured by a universal joint 26 to the shaft 22 is a connection 27, the other end of whichy is secured by a universal joint 28 to a shaft'29, journaled in a ring frame 30 surrounding the jet nozzle 31 through which the forced vdraft passes to the stack 4. The effective port area of the nozzle openingt32 from` port 31 is adapted `to be varied by an expansible and contractible ring consisting of a plurality of segments 33 in Aframe 30, these being hinged one to the other` by joints 34, as best seen in Fig. V. Twoof the segments 33V and 33 are provided with off-set ears 35 and 36 which are connected to the ears 37and 38 on the respective sliding blocks 39 and 40, which are provided with rack teeth 41 and 42 to mesh with the pinion 43 on shaft 29. The meeting edges ofthe segments 33 and 33" are recessed as at 44v and 45 to receive a backing abutment 446 fast to the frame 30 so that the said segments will be held in operative position with respect to the bars 39 and 40. In Fig. V, the ring-shaped valve device isshown in its constrictedv position to reduce the effective port area lof the ejector nozzle 31. The tongue and groove connections between the segments 33, shown in Fig. VII, permit enough lost motion to allow the ring to expand to increasethe Veffective port area of thenozzle 31. The abutment 46 constitutes a guide and an abutment for'the segments 33 and33 so that the'ring will be maintained in its proper relative position andv to prevent displacement or .binding of the racks 39 and40,

. which are connected to said segments. Since the ring is'shown in its constricted position, in F ig.'V with the pinion43 meshing with the -racks 39 and 40, it is obvious-that when the'pinion rotates inone direction, the racks 39 and Y40, shown in Fig. VI, willV move in opposite directions to expand the ringand whenthe pinion is rotated,- in an opposite direction, the racks will be moved contrawise to constrict ther-ing.

The smoke passing through the nozzle 31 has a tendency to leave depositsofcarbon upon the ring seatand in the ring joints as well as to accumulatefaround the otheroperating parts. It, therefore, becomes-desirable to remove or prevent the accumulation of these carbon deposits and to this `end I have provided means whereby a Huid under pressure, preferably steam, may be .directed against the end of the nozzle and the moving parts to carry away any carbon which hasvbeen deposited bythe smoke.

Surrounding the segments of ,the ring which constitutes the draft controller is a lubricating space 47 having inlet ports 48 and 49 communicating with a steam pipeV 50 leading from the fountain 51 and havabove described.

ing valves 52 and 53 on opposite sides of the valve lubricant-containing cup 54 whereby steam may be'admitted from the fountain to the space 47 through the branch ports v 48 and 49 to lubricate the ring. The forced crease the velocity of the gaseous iluid'fair)` passing through the fire -boX Vand out through the stack, following the natural law of rates of' flow. Therefore, -the draft through the fire-box will be at the maXimum for the given amount of steam issuing from the ejector nozzle. When the Vproducts of combustion in the fire-box` have raised the temperature of the water in the boiler and consequently generated steam at a sufficient pressure, sayr'180 pounds, the steam'passing lfrom dome 5 through pipe 6 to chamber 8 .will raise the piston `13k against the action of thespring 12 untilit passes the inlet to the by-pass port 11l whereupon the piston 14 will be raised, rotating the gear 19 and through it, imparting movement to the ,'gear'21 soas to rotate the link 27 and impart a krotary movement tofthe shaft 29, causing'the pinion 43 to move the bars 39 and 40 inV opposite directions and as these are connected to the segmentsV 33 and 33, the ring will' beexpanded,andv

thereby increase the effective port area of the nozzle 32, quickly Vcutting down' the velocity of air and burnt gases passin'gto the stack. As a result, the draft in the fire-box will be decreased and the combusti'- ble material will be consumed Vat a slower' rate, permitting the steam pressure tobe maintalned or allowingja drop 1n pressure but not `permitting the pressure to rise so iifoV that thel steam will be blown off into atmosphere'through the'blow-of valve in ,the boiler and thereby permit a consumption of fuel to no advantage.

If there isa drop in pressure, the spring 12 will move the valve 13 ktoward the end-of f the cylinder`7, closingoff communication between pipe 6 and by-pass 11, `and permit the piston14'to drop, the dropping of the piston being assisted by the weightedlever on shaft 2O of gear 19, as best seen inV Fig. IV. As the 'piston 14 drops and the` gear 19 is rotated, a reverse rotation will be imparted to gear 21, Vcausing the link 27 to berotated in arev'erse direction and thereby impart a movement lto the shaft 29 and pinion 43, which will cause the bars 39 and 40 :to be moved ina direction to bring the adjacent edges of the segments 33 and 33 one toward the other and thereby constrict the effective port area of port 32 and again increase the velocity of the draft t o increase the consumption of the combustible material in the fire-box andV thereby raise a steam pressure.

The alternate operations may continue 1n a Well understood manner, it being obvious that the velocity of the draft Will be in 1nverse ratio to the pressure in the boiler.

Under certain conditions the lubricator 54 may not be considered essential to the op-A eration of the mechanism; for example, un-

der certain conditions the lubricating cup 54 may be removed or the valve 54 may be closed so that only steam Will be discharged through the ports 48 and 49 to prevent the accumulation of carbon, dust, dirt or other foreign matter.

If dry or super-heated steam is introduced through the pipe 50 and ports 48 and 49, the seat for the contractible ring or nozzle Will be kept free of accumulations, as Will also the hinged joints and adjacent parts. Therefore, I may find it unnecessary in all instances to introduce a lubricant. The fluid, Whether steam from the boileror superheater, will be effective at all times without the necessity of employing a lubricant.y

I, therefore, do not Want to be limited to the use of lubricant for all purposes, the invention `contemplating the admission of a iuid with or Without the lubricant.

Vhat I claim and desire to secure by Letters-Patent Ais 1. In a draft regulator for ysteam boiler furnaces, a nozzle having an expansible and contractible ring atY its outlet and to vary the effective port area of said nozzle, means responsive to boiler pressure for expanding and contracting said ring, and a boiler pressure actuated lubricating means for supplying lubricant to said ring.

v2. In a device of the class described, an expansible and contractible tip for forced draft nozzles, and means for expanding and contracting said tip including a cylinder having Vtwo compartments, means for bypassing the steam around one compartment into the other, a piston in the latter compartment having a rack foroperating gearing to expand and contract the tip, anda valve Vnormally closing the inlet to the by-pass from an inlet port in the cylinder adjacent thereto.

3. In a draft regulator for steam boiler furnaces, an expansible and contractible member for engagement with the outlet end of a nozzle, meansfor operating said member comprising gearing, and means foroperating the gearing comprising a rackfor engagement With one of the gears, a counteracting Weighted lever connected to one of the gears, a piston on the rack, a cylinder in which the piston reciprocates, a second named cylinder, and a pressure valve in thek second mentioned cylinder controlling the passage of steam into the first named cylinder. Y

4. A draft regulator for steam boiler furnaces comprising an expansible and contractible member consisting of segments hinged together,means for expanding and contracting said member, a casing for said member, and a steam pipe leading into the casing to lubricate the same.

. 5. A draft regulator for steam boiler furnaces comprising an expansible and contractible member consisting vof segments hinged together, means for expanding and contracting said member, a casing for said membera steamy pipe leading into the casing to lubricate the same, and a grease cup carried by the steam pipe.

6. In a draftregulator for steam boiler furnaces, a nozzle having an expansible and contractible 4 portion to vary the effective port area thereof, and a boiler pressure actuated lubricating means for supplying lubricant to said expansible and contractiblev portion. c

7. In a draftregulator for steam boiler furnaces, a nozzle having an expansible and contractible port area changing means, a tubular connection between the steam boiler and the means, and a lubricant container communicating with the tubular connection.v

adjacent to the movable parts to remove accumulations therefrom.

j 9. In a draft regulator for steam boiler furnaces, a nozzle having an expansible and contractible port area changing means, and a conduit connected to the steam boiler and having a discharge end in proximity to the expansible and contractible port area changing means to direct fluid under pressure thereagainst.

10. Ina draft regulator for steam boiler furnaces,a nozzle having an expansible and contractible port area changing means, means responsive to variations in boiler pressure for operating said port area'changing means, and a fluid discharge port adjacent to the expansible and contractible port area changing means to direct fluid under pressure against the expansible and contractible port area changing means to maintain it free from accumulations of carbon and the like.

In testimony whereof I affix my signature. 

